1. Field of the Invention
This invention relates, in general, to methods for repairing cracks in pavement and recreational surfaces.
2. Description of the Art
Methods for repairing cracks in paving materials, such as roadways, pavement and other concrete or asphalt surfaces, such as recreational surfaces, tennis courts, outdoor basketball courts, volleyball courts and running tracks, generally involve cleaning the crack of loose debris and then filling the crack with a crack filler material which hardens to a solid state forming a smooth surface with the surrounding pavement surface. This is more economical than re-paving the entire section of pavement which may contain only one or a few cracks.
However, such a crack repair method is viewed as only a temporary repair as progressive maintenance must be applied due to continued crack enlargement under changing environmental conditions, including temperature and moisture fluctuations. Repaired cracks continue to expand since current repair methods do not alleviate the stresses which cause crack formation or movement.
In an attempt to lengthen the repair times between maintaining a repaired crack in a pavement or other surface, a strong surface has been applied or formed above the repaired crack, typically of an adhesive impregnated fiberglass sheet. However, the fiberglass sheet, while presenting a solid, hard surface, is also susceptible to tears and cracks caused by enlargement or movement of the underlying repaired crack.
In an attempt to address this problem, other crack repair methods have been developed which utilize a so-called xe2x80x9cslip-sheetxe2x80x9d principle. In these methods, after the crack is cleaned and filled with a crack filler to the surface level of the surrounding pavement or recreational surface, a slip-sheet which can be adhered to the top surface of the crack filler but which presents a nonadhesive outer surface is applied over the crack. One layer of sheet material, was applied over the slip-sheet and adhered at peripheral edges to the surrounding pavement or recreational surface. This isolates the sheet from the slip-sheet thereby enabling the slip-sheet to move with crack movement or enlargement without generating stresses in the outermost sheet which could tear or rip the outer sheet. Several of these previously devised crack repair methods make use of adhesive-back tape, such as duct tape, which has a non-adhering polyethylene outer surface.
The present Applicant had devised a crack repair method utilizing two 2-inch wide duct tape strips which are applied side edge to side edge over a cleaned and filled crack. In some applications, Applicant used a single 3-inch wide strip of duct tape. The plastic backing of the duct tape prevents adherence to overlaying sheets. The Applicant applied an adhesive layer over and beyond the duct tape for a predetermined width outside of the outer periphery of the tape strips before applying a single 9-inch wide sheet of stretchable fabric. Another wider area of adhesive was applied over the stretchable fabric sheet for adhering a second, wider stretchable fabric sheet of approximately twice the width as the first fabric sheet. After adhesive is applied to the edges of the outermost stretchable fabric sheet, two 6-inch wide strips of fiberglass sheet were applied to the side edges of the outermost stretchable sheet.
While Applicant""s prior crack repair method significantly lengthened the time between required maintenance to a repaired crack, the method still experienced failures caused by crack reformation.
Thus, it would be desirable to provide an improved pavement crack repair method which significantly reduces the reformation of repaired cracks in pavement or other surfaces. It would also be desirable to provide an improved crack repair method which returns the pavement or recreational surface to a substantially uniform use surface.
The present invention is a crack repair method for repairing cracks in pavement which provides a slip-sheet between the filled crack and an overlaying stretchable fabric layer wherein the fabric layer is capable of stretching under stresses induced by crack growth and reformation without rupturing the crack repair patch.
According to one aspect of the present crack repair method, the method is devised for repairing cracks in a pavement and comprises the steps of:
cleaning the crack of debris;
filling the crack with a crack filler hardenable to a solid state;
applying a slip layer over the filled crack and beyond the crack, the slip layer being greater than about four inches wide with one surface adhesively fixed to the filled crack and an opposed non-adherable surface facing away from the filled crack;
applying a first adhesive layer over the slip layer and a first distance beyond opposed side edges of the slip layer; and
applying a first sheet of stretchable material over the first adhesive layer.
Optionally, the method further includes the steps of:
applying a second adhesive layer over the first sheet of stretchable material and to a second distance beyond the edges of the first sheet of stretchable material; and
applying a second sheet of stretchable material over the second adhesive layer to the full second distance of application of the second adhesive layer.
In another aspect, the method further includes the steps of:
applying a third adhesive layer over the second sheet to a third distance beyond the second flexible sheet; and
applying two outermost strips over the edges of the second sheet wherein the portions of the outermost strips are bonded to the second sheet and to the top surface of the pavement beyond the side edges of the second sheet.
Preferably, the first and second sheets are formed of stitch bonded polyester material. The two outermost strips are preferably formed of fiberglass fabric.
In one aspect of the invention, the slip layer is formed of a single layer of an adhesive back tape in a single width strip or two or more side-by-side strips.
In another aspect of the invention, the slip layer is formed by a sheet of plastic material, such as polyethylene, Mylar, Teflon, etc., which is carried on the bottom surface of the first stretchable sheet and overlays the crack when the first sheet is centered over the crack. The outer side edges of the first sheet are fixed to the top surface of the pavement surrounding the crack and beyond the outer edges of the plastic sheet by an adhesive layer previously applied over the filled crack for a predetermined distance beyond the edges of the crack to the full width of the first sheet.
The crack repair method of the present invention overcomes deficiencies found in previously devised crack repair methods for pavement and other recreational surfaces by providing a long life crack repair patch which allows stretching or elongation of the stretchable fabric which is isolated from the filled crack by a slip layer so as to be isolated from stresses created by crack growth and/or reformation.
The crack repair method of present invention provides a crack repair which minimizes tearing of the repair materials. In this way, the crack repair patch remains effective for a longer period of time thereby enabling the pavement or recreational surface to be used for its intended purpose without deterioration of the surface.